Put outside in the middle of trench for seed (4,3)
I believe the answer is:
pine nut
'for seed' is the definition.
(seed of a pine tree)
'put outside in the middle of trench' is the wordplay.
'outside' indicates putting letters inside.
'the middle of' means to look at the middle letters.
The middle of 'trench' is 'en'.
'in'+'en'='inen'
'put' enclosing 'inen' is 'PINE NUT'.
(Another definition for pine nut that I've seen is " Producer of evergreen".)
I've seen this clue in the Sydney Morning Herald.
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